Tooling for inserting Z-pins

Abstract

I achieve positive, accurate placement of Z-pins in resin composite parts using a tool to guide the pins from the foam preform into the part. The tool has a reciprocating piston for crushing the foam to insert the pins and uses a positive stop to control penetration depth and positioning of the Z-pins. The tool also includes a plurality of bores for guiding the individual pins from the foam preform to the part while separating the part from the foam preform.

I claim: 
     
       1. A Z-pin positioning tool for accurately and reliably inserting Z-pins from a pin-carrying foam into a resin composite part, comprising: (a) a reciprocating piston slidingly engaged in a housing;   (b) a removable pin placement member temporarily rigidly fixed in the housing to form one end wall of the housing and to define a cavity in the housing between the piston and pin placement member for receiving the pin-carrying foam, the pin placement member including a plurality of bores extending through the member in a regular pattern the bores extending from an outer face on a surface adjacent to the cavity and a part receiving face on a surface opposite the cavity so that the bores define a pin placement orientation in a part seated on the receiving face and for guiding pins in the foam into the part upon crushing motion of the piston against the foam;   (c) motive means for moving the piston toward the member to crush the foam to insert the pins from the foam through the bores into the part; and   (d) a part seat fabricated into the receiving face of the pin placement member adapted for seating the part for insertion of the Z-pins from the pin carrying foam through the bores during motion of the piston toward the member.   
     
     
       2. The tool of claim 1 wherein the pin placement member has a thickness which functions as a gauge for the height the pins protrude from the part following their insertion. 
     
     
       3. The tool of claim 1 wherein each bore has a converging funnel entry facing the cavity on the outer face of the member. 
     
     
       4. The tool of claim 1 wherein the piston and pin placement member are made from metal and are capable of withstanding temperatures and pressures needed to cure the resin composite part while the part is positioned on the tool; and   the motive means includes a pneumatic pressure chamber behind the piston.   
     
     
       5. The tool of claim 4 further comprising an adjustable stop for adjusting the relative motion of the piston and pin placement member during the crushing motion. 
     
     
       6. The tool of claim 1 wherein the bores are sized to receive carbon fibers from the foam. 
     
     
       7. The tool of claim 1 wherein the bores provide an areal density in the part of about 0.375 to 2.0%. 
     
     
       8. The tool of claim 1 wherein the bores are substantially normal to the outer face and to the receiving face.